MOSgated devices, such as power MOSFETs and IGBTs are very well known, and have a gate electrode, usually made of conductive polysilicon, which must be electrically insulated from the source electrode (or emitter electrode) and yet must be electrically connected to an external metallic gate conductor or gate pad, usually of aluminum. In the self aligned contact power MOSFET, contact to the source is made in the active area, using spacer technology. However, the gate metal-to-gate polysilicon contact at the gate pad has required the use of a separate photo mask step.
It is desirable to reduce the number of photomask steps needed in a manufacturing process to reduce cost and to increase yield of devices from a wafer.
The present invention provides a novel process which eliminates the need for a separate mask for the gate polysilicon to gate metal connection in a manufacturing process.